Table 1.

A comparison of the old and new guidelines for the detection and treatment of hypertension (based on Ramsey et al¹³).

New guidelines
Group	Definition	Treatment
N5	SBP = >200 mmHg or DBP = >110 mmHg	Drugs
N4	SBP = 160–199 mmHg or DBP = 100–109 mmHg	Drugs
N3(ii)	SBP = 140–159 mmHg or DBP = 90–99 mmHg; and clinical reason for screen or a high 10-year risk of CHD	Drugs
N3(i)	SBP = 140–159 mmHg or DBP= 90–99 mmHg; and no clinical reason for screen and a low 10-year risk of CHD	Monitoring
N2	SBP = 135–139 mmHg or DBP = 85–89 mmHg	Monitoring (frequency depending on reading)
N1	SBP = <135 mmHg and DBP<85 mmHg	Reassessment in 5 years

Old guidelines
Group	Definition	Treatment
O4	DBP = >100 mmHg	Drugs
O3(i)	DBP = 90–99 mmHg; and clinical reason for screen or a higher 10-year risk of CHD	Drugs
O3(ii)	DBP = 90–99 mmHg; and no clinical reason for screen and a low 10-year risk of CHD	Monitoring
O2	SBP = >160 and aged over 60 years	Drugs
O1	All other patients	No treatment

SBP = systolic blood pressure; DBP = diastolic blood pressure; CHD = coronary heart disease.